This invention relates to aquarium filters, and more particularly to an external aquarium filter utilizing a magnetically coupled pump impeller and having an easily removable, unitary intake assembly.
Aquarium filters are regularly utilized for the purpose of aeration and filtration of the aquarium water and at the same time provide circulation to such water. One type of aquarium filter is an externally mounted filter which houses filtration equipment and includes a pumping mechanism which induces the circulation of water from the aquarium through the filtration equipment and then returns the clean water to the aquarium.
In order to provide circulation of the water, a suitably adapted pumping mechanism must be provided within the water flow path. In some filters, a motor driving a pump is hermetically enclosed and positioned directly within the flow path. However, such pumping mechanisms are costly and difficult to repair.
In other prior art devices the motor is maintained in a separate location from the flow path and is magnetically coupled to an impeller which is positioned in the flow path. One such prior art device is described in U.S. Pat. No. 3,512,646. Another magnetically coupled aquarium filter is described in U.S. Pat. No. 4,093,547. In both these devices, the entire motor, including the stator and rotor are mounted externally of the flow path and a separate impeller is magnetically coupled to the rotor. However, it is difficult to gain access and clean the impeller.
One type of motor pump assembly which permits completely submerged operation of the motor is described in U.S. Pat. No. 3,853,429. In this type, again it is difficult to gain access to the parts of the motor assembly in order to provide cleaning and repair.
In the externally mounted aquarium filters, an intake mechanism must be provided in order to supply the contaminated aquarium water to the filter. This intake mechanism and impeller has a tendency of getting clogged by bits of aquatic vegetation and other detritus that accumulates in an aquarium. It is therefore of importance to be able to easily remove the intake assembly and impeller assembly in order to clean it. In most cases, since the intake assembly is associated with the impeller, the problem of cleaning the intake assembly is compounded by the necessity to also remove the impeller which is virtually inaccessible without emptying and inverting the filter.
Maintenance of filtration devices requires replacement of the filtering material and also requires regular cleaning of the intake assembly and especially the impeller unit. With prior art filtration devices the intake assembly is often an integral part of the entire device and it is therefore necessary to remove and clean out the entire device in order to remove any of the contamination particles clogging the flow path. In addition, in order to gain access to the impeller, it was necessary to substantially disassemble the entire device. Accordingly, cleaning, repairing and maintenance of prior and filtration devices presented considerable problems.